Single-wire selective signaling and intercommunicating telephone



No. 770,556. PATENTED SEPT. 20, 1904. J. A. BROWN.

CTIVE SIGNALING AND INTERGOMMUNIOATING SINGLE WIRE SELE TELEPHONE.

APPLICATION IILED 0 3 SHEETS--SHEET 1.

NO MODEL.

5111 van for No. 770,656. PATENTED SEPT. 20, 1904.

J. A. BROWN. SINGLE WIRE SELECTIVE SIGNALING ND INTEROOMMUNIGATING TELEPHONE.

NO MODEL APPLIUATION FILED OCT. 28, 1903. 3 SHBETS SHEET 2 J79, 5

No. 770,556. PATENTED SEPT. 20, 1904.

- J. A. BROWN. SINGLE WIRE SELECTIVE SIGNALING AND INTERGOMMUNICATI'NG TELEPHONE.

APPLICATION FILED 0012s, 1903.

3 SHEETS-SHEET 3.

NO MODEL.

inferna /0" Patented September 20, 1904.

PATENT OEEIcE.

JOHN A. BROWN, OF BLYTHEWOOD, SOUTH CAROLINA.

SINGLE-WIRE SELECTIVE SIGNALING AND INTERCOMMUNICATING TELEPHONE.

SPECIFICATION forming part of Letters Patent No. 770,556, dated September 20, 1904.

Application filed Ot0ber 28, 1903. Serial No. 178,812. (No model.)

To all whom it may concern:

Be it known that I, JOHN A. BROWN, a citizen of the United States, residing at Blythewood, in the county of Fairfield and State of South Carolina, haveinvented certain new and useful Improvements in Single-Wire Selective Signaling and Intercommunicating Telephones; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference beinghad to the accompanying drawings, and to the figures of reference marked thereon, which form a part of'this specification.

My invention relates to telephone systems, and has for its object to provide a single-wire selective signaling and intercommunicating telephone.

A further object of my invention is to provide a telephone system which is so constructed for use on party-lines and in villages that one of the stations can be brought into communication with any other station without any of the remaining stations being able to hear or in any way interfere with the communication of the two stations engaged without the aid of a switchboard or central office.

A further object of my invention is to provide a telephone system for party-lines wherein after communication has been established between two stations none ofthe remaining stations can break in or use the wire. In other words, the two stations in communication have entire control of the line.

A further object of my invention is to provide an automatic call the mechanism for which is so arranged that when one-station gets into communication with any other station the latter station is at the same time and automatically called.

A further object of my invention is to provide a metallic telephone system for partylines and villages which is simple in its construction, easy and cheap to manufacture, utilizing but a single wire, and composed of a minimum number of parts.

With all these objects in view my invention consists in the means I employ for bringing two stations of a party-line into communication without allowing the remaining stations to be in communication or in any way interfere with the communication so established or use the line in any way.

My invention further consists in the means employed for automatically calling any station on a party-line and at the same time bringing said station into communication with the calling-station.

My invention further consists in certain details of construction and in combination of parts which will be first fully described, and afterward specifically pointed out in the appended claims.

Referring to the accompanying drawings, Figure 1 is an elevation of the telephone-case with door open, showing interior mechanism. Fig. 2 is a plan view showing system of wiring of Fig. 1 and a party-line of eight stations. Fig. 3 isan inside view of the left side of casing shown in Fig. 1. Fig. 4 is a vertical cross-section taken on lines 4 4 of Fig. 1. Fig. 5 is a perspective view of the communicating mechanism. Fig. 6 is a detail of the rotary operating-crank, taken from the inside of the telephone-case. Fig. 7 is a detail view of the double-battery switch and button for bringing the batteries of a station into connection with the line. Fig. 8 is a plan view showing system of wiring call-bell, which for the sake of clearness has been illustrated separately from the wiring of the station.

Like numerals of reference indicate the same parts throughout the several figures, in which- 9 is the telephone-case, of any suitable size or shape, having a door 10. The interior of the case is divided, preferably, into three compartments 11, 12, and 13, and shelves 14 and 15 divide the interior, as shown in Fig. 1. In the lower compartment, 11, I prefer to place the batteries, composed, preferably, of two cells 16 and 17, one of which is employed for the call-bell and the two combined for the transmission of speech. Above said batteryoompartment 11 in compartment 12 I pivot the switch-hook-receiver holder 18 at 19, and upon the floor of shelf 141 provide two spring: contacts 20 and 21, to be thrown into contact by the switch-hook-receiver holder when the receiver is hung up, which cuts out the local battery, as is usually done. On the right side of the casing 9 I provide a spring-contact 22, to be engaged by the switch-hook-receiver holder 18 to cut out the bell-battery when the receiver is taken down.

Above the shelf in compartment 13 I locate the mechanism in which my invention principally consists. Resting on shelf 15 is an electric magnet 23, similar in detail to the usual telegraph-sounder, the sounding-key 24 of which is pivoted at 25, and connected thereto is the arm 26, capable of angular adjustment thereto. Pivoted to said arm at 27 'is the pawl 28, in engagement with the toothed wheel 29, secured on the shaft 30, and secured on the outer end of said shaft 30 is the dial 31. Secured in front of said toothed wheel 29 and in contact therewith is a wheel 32, of less diameter, and normally in engagement with the periphery thereof is a brake-lever 33, pivoted at 34 to the inside of the casing. A spring 35, havinga compressionstraim is secured to said brake-lever and holds the same in constant engagement with the brake-wheel 32. Secured above said dial 31 and pivoted on a shaft 36 is a rocking lever 37, having a downwardly-projecting'extension 38, and permanently secured to said dial is apin 39,which engages said extension 38, as will be hereinafter described. Secured to the side of the casing 9, just below the rocking lever 37,'are two binding-posts 40 and 41, to one of which posts, 41, the receiver is connected and to the other post the induction-coil 42, located on the door 10, is connected. On said rocking lever 37 is a metallic contact 43, which normally rests upon said binding-posts, as shown in Figs. 1 and 5, and when in this position the receiver 44 and transmitter 45 are cut out'of the linecircuit.

Secured to the switch-hook-receiver holder 18, as shown in Figs. 1 and 5, is a link 46, which passes up and is connected to a metal lic contact 47 pivoted at 48 to the inside of the casing. When the switch-hook-receiver holder is down, the metallic contact rests upon the binding-posts 40 and 41 and cuts out the receiver 44 and transmitter 45. When the receiver is off the hook, however, said metallic contact is raised off the binding-posts 40 and 41, which throws into the circuit the receiver 44 and transmitter, all of which will be fully set forth when describing the wiring in connection with Fig. 2. Below said binding-posts 40 and 41 is the other binding-post, 49, for the return-wire of the receiver.

Referring now to the dial 31, it will be seen that the same is numbered from 1 to 8, as Fig. 2 shows a line having eight Sta-- tions, although it is of course practical to numper a disk up to perhaps fifty, so as to accommodate a party-line of fifty stations. Considering the telephone shown in Fig. 1 and enlarged in Fig. 2 to be the second station on the line and bearing the number 2, a permanent pin 39 is secured at the numeral '2 on the dial 31, as shown in Fig. 1. is desired to communicate with any other station on the line, a removable pin 50 is inserted in the dial 31 at the number of the station with which communication is desired, as will be afterward fully described. In order to prevent the line batteries 51 from being burned out, I provide a double switchbutton 52, which breaks the short circuit of the line-circuit and cuts the line-batteries in only when calling and when getting into communication.

Secured on the outside of the casing is the rotary operating-crank 53, consisting of a crank and handle on the outside of the case having a short shaft 54 extending through the casing and acrank-arm 55, formed thereon, on the inner side of the casing. A roller 56 is carried on said latter crank-arm 55, adapted to engage the pivoted contact 57 which is normally held in contact with the stationary contact 58 by means of the spring 59, Fig. 6. When the operating-crank is revolved, the roller 56 forces the pivoted contact 57 out of contact with the stationary contact and breaks the circuit, and when the roller 56 passes out of line with the pivoted contact the spring 59 draws the pivoted contact into its normal position. Thus the circuit is rapidly opened and closed.

Referring now to the double switch-button 52, Fig. 7, the same consists of two springcontacts 60 and 61, connected to the line, Fig. 1, and a stationary metallic contact 62, secured above said spring-contacts. Secured on said stationary contact is a strip of non-conducting material 63, and normally in position above said'non-conducting strip and adapted to be forced into a contact with the spring-contacts 60 and 61 are two spring-contacts 64 and 65, connected to the line-batteries. A button 66 rests upon said latter spring-contacts 64 and 65, and when the said button is depressed the said latter spring-contacts are forced down into a contact with the spring-contacts 60 and 61 and forces the same down and out of contact with the stationary contact 62, which breaks the short circuit on the line-circuit and cuts in the line-batteries.

Referring now to Fig. 2, which illustrates the system and wiring, I show eight stations, (designated from 1 to 8.) The second or station 2 is shown enlarged and with the interior wiring. It will be seen that the local batteries 16 and 17 are wired to the inductioncoil 42 and thence through the transmitter 45 When it to the switch-hook-receiver holder 18 and back to the batteries. The line-wire 67 enters the station 2 and passes into the casing and through the operating switch-crank 53 and through the electromagnet 23, thence to the binding-post 40, and down into the induction-coil 42, from which it passes up to the binding-post 49 and into the receiver, returning to the binding-post 41, then to the point 68, where it leaves the station and leads to the double switch-button 52, where it is cut into the line-batteries 51 by said switch or led to the next station. Bridging across the loop in the line from the points 69 to is a condenser 71, which overcomes'the resistance of the electromagnet, so that the speech is transmitted through said condenser by the induced current without passing through the electromagnet. When the metal contacts a3 and 47 rest upon the binding-posts L0 and &1, Figs. 1 and 5, it is obvious that the current is shortcircuited from both the transmitter and receiver, which renders the station incapable of breaking into the line or of overhearing a communication between stations on either side. As to the call or hell wiring, it will be seen from Fig. 8 that one of the local cells 16 is wired directly to the bell 72, thence to the forked contact 75, then to the switch of the receiver-holder 18 back to the battery. When the switch-hook-receiver holder is down, it cuts in the battery as far as the forked contact, and when the pivoted-wedge contact 7 4, Fig. 5, is dropped into the forked contact the circuit to the bell is made.

To pass now to the operation, it will be seen that the pivoted-wedge contact 73 is pivoted to the rocking lever 37 at 74:, Fig. 5. When it is desired to communicate with any station on the line, the removable pin 50 is inserted in the dial 31 at the number of the station with which communication is desired, and if, for instance, that station were No. 5, the permanent pin in the dial of No. 5 station would be at the number 5. Having then inserted the removable pin 50 in the dial 31 at No. 5 of the calling-station, the operating-crank is revolved, which, as before described, rapidly opens and closes the circuit which oscillates the .keyv of the electromagnet. As said key is lowered when the circuit is closed, it forces the arm 26 of said key inwardly, and as the pawl 28 is pivoted to said arm andis in engagement with the toothed wheel it moves said wheel one notch, the brake-lever 33 holding the toothed Wheel and preventing the same from flirting. As said toothed wheel is revolved the dial 31 is revolved with it, and as soon as the removable pin 50 in No. 5 of the dial comes in contact with the projection 38 on the rocking lever and bears against the same the rocking lever is raised, which carries the metal-wedge contact 73 down in contact with the forked contact 75. This closes the bell-circuit and calls the station 5, and the dial 31 and toothed wheel 29 revolve in station 5 exactly as in the calling-station. Asa matter of fact the dials of all of the stations revolve together; but as there is only one dial in all the stations having a permanent pin at N o. 5 this station so having the permanent pin at No. 5 is the only one on the line which is called. As a matter of fact the bell of each station rings as their pins 39 come in contact with the projection 38; but the bells only ring an instant and is not such a ringing as would lead the subscribers to mistake it for a call, for the reason that when a station gets into communication with another station the ringing of the bell is continuous and uninterrupted until the receiver is removed from its hook at the station called. At the same time that the bell-circuit is closed the metal contact 43 on the endof the rocking lever 37 is raised off the binding-postslO and 41, which cuts in the receiver and transmitter of both the calling station and station No. 5 after the receiver of both stations have been taken down off their hooks, which'allows the switch-hook receiver holders 18 to raise and lift the metal contacts 47 of both stations ofl' the bindingposts 40 and 4:1. The last-mentioned metal contacts 47 of both stations accomplish the result of cutting out or short-circuiting the receivers and transmitters until the call has been made at station N o. 5 and commuication established, as the metal contacts 47 cut out the resistance of the direct current passing through the receivers and transmitters until communication has been'eflected. When the communication is at an end, the operatingcrank 53 is turned until the pins 5 of both stations pass out of engagement with the extensions 38 on the rocking levers 37, which again throws the metallic contacts 43 in contact with the binding-posts 40 and 41, again cutting out the receivers and transmitters and breaking the bell or call circuit by raising the pivotedwedge contact 73 out of the forked contact 75. When calling and turning the operating-cran k 53, the button of the double switch 52iis depressed, which cuts in the line-batteries to the line-circuit, and when communication has been established the hand is taken from the button, which cuts out the line-batteries from the line-circuit and prevents them from being wasted or burned out, which would occur were the connection permanent.

When any two stations are in communication, the induced current transmitting the speech does not pass through the receivers and transmitters of the intermediate stations, but, as before stated, is bridged by means of the condenser in each station. Should, however, during communication between two stations another station attempt to break into the line by calling another station, the direct current from the line-battery necessary to bring the station called into communication cannot bridge across the receivers and transmitters of the two stations already in communication, for the well-known reason that a direct current cannot pass through a condenser. In order, therefore, to break into the line during communication between two stations, it would be necessary'for the direct current to pass through the two receivers, two transmitters, and two induction-coils of the two stations already in communication, which it cannot do, as a direct current of sufiicient strength for calling the stations cannot overcome the resistance of the receivers, transmitters, and induction-coils of the two stations already in communication. It is thus seen that after communication has been established between two stations said two stations have entire control of the line.

What I claim as my invention, and desire to secure by Letters Patent of the United States,

1. In a telephone system, the combination with a single wire of a series of telephone-stations having suitable transmitters, receivers and call-bells, and a local battery in each station, an electromagnet and means for operat ing the same, a dial adapted to be operated by said electromagnet having a permanent attachment thereon corresponding to the number of the station, and a removable attachment for said dial capable of being attached to said dial at a point corresponding with any other one of the said series of telephone-stations, means adapted to be operated by the said attachments on said dial to simultaneously call any predetermined station, and to allow the receivers and transmitters of both stations to be cut into the line at the option of the operators. I

2. In a telephone system, the combination with a single wire, of a series of telephonestations having suitable receivers, transmitters and call-bells, the transmitters and receivers of which are normally cut out of the line, select signaling means in each station, a device for short-circuiting the transmitter and receiver in each station, said device being operated by the said signaling means simultaneously in the stations brought into communication, and a short-circuiting device in each station adapted to be operated at the option of the operators to cut the transmitters and receivers into the line.

3. In a telephone system, the combination of a series of telephone-stations having suitable transmitters receivers and call-bells, the receivers and transmitters of each station being normally cut out of the line, means in each station for calling a predetermined station, a device for short-circuiting the receivers and transmitters in each station adapted to be operated by said calling means, and a short-circuiting device in each station for cutting into the line the receivers and transmitters of the stations in communication.

4:. In a telephone system, the combination of a series of telephone-stations, suitable receivers and transmitters in each'station, selective signaling means in each station, a device for short-circuiting the receivers and transmitters in each station adapted to be operated simultaneously by said selective signaling means in the stations in communication, a short-circuiting device in each station adapted to be operated at the option of the operators to cut into the line the receivers and transmitters of the stations in communication and a condenser in each station for overcoming the resistance of the receivers and transmitters of the stations in communication.

5. In a telephone system, the combination of a series of telephone-stations having suitable receivers, transmitters and signaling means, a short-circuiting device for, normally cutting out of the line the receivers and transmitters in each station, said short-circuiting device being adapted to be operated in a predetermined station by the said signaling means in' a calling-station, a receiver-holder and means operated thereby for independently short-circuiting the line to cut out the receivers and transmitters, said means cutting in the receiver and transmitter when the receiver is raised from the said receiver-holder.

In testimony whereof I affiX my signature in presence of two Witnesses.

' J OHN A. BROWN.

Witnesses:

HENRIETTE 'KAHN, C. HUGH DUFFY. 

